Mobile platforms such as aircraft, busses, trains, ships, rotorcraft, etc., typically require an externally mounted antenna to enable communications with a base station transceiver. In an aircraft application, the antenna would typically be mounted on an exterior surface of the fuselage on the crown of the fuselage. For example, the CONNEXION BY BOEINGSM system enables high speed transmission of digital information from a base transceiver directly to high speed mobile platforms such as (but not limited to) commercial jet aircraft, or via a transponded satellite communications link.
With any mobile platform, aerodynamics is typically an important consideration. With high speed moving aircraft such as commercial jet aircraft, aerodynamics becomes an especially important consideration in the performance of the aircraft and its operating costs. However, with any form of airborne mobile platform, the mounting of an antenna on an external surface thereof will generally operate to negatively affect the aerodynamics of the mobile platform. To protect the antenna and to further mitigate the negative aerodynamic impact of the antenna, a fairing (also referred to as a “radome”) may be mounted over the antenna to enclose the antenna over a portion of an exterior surface of the mobile platform. In this instance, the shape of the fairing is important to providing good aerodynamic performance, and therefore ameliorating the negative aerodynamic influence that would otherwise be introduced by the presence of the antenna on the exterior surface of the mobile platform.
Present day fairings, however, are not especially well suited (i.e., shaped) to cover antennas having dimensions required for use with high frequency, satellite based communication systems. Such antennas often project up to 12 inches (30.48 cm) or more above the outer surface of the mobile platform upon which they are mounted, and therefore present a significant “protrusion” or projection that can negatively affect the aerodynamic performance and operational cost of a high speed mobile platform.
When an airfoil is employed on a high speed mobile platform, similar aerodynamic considerations must be considered. For example, the airfoil should have a curvature that avoids shocks at the peak MACH speed that the mobile platform will experience. This requires the local MACH speeds of airflow over various portions of the airfoil to remain at or below about 1.2 MACH. The airfoil should not have significant unstable flow characteristic, i.e., flow separation at the aircraft cruise flight speed, which can shorten the life of the structural hardware due to fatigue damage.